(1) Field of the Invention
The present invention relates to network management apparatuses, and more particularly, to a network management apparatus that performs network management operations.
(2) Description of the Related Art
In recent years, a wider variety of information network services have been expected, and the information infrastructure for providing these services has become larger and complicated. In this trend, there is an increasing demand for network management apparatuses (NMA) that perform maintenance management of network devices (or network elements: NEs) such as transmission devices that constitute a network.
To change the current state of a NE, an operator inputs a status change request into a network management apparatus. Upon receipt of the status change request from the operator, the network management apparatus generates a command corresponding to the request, and transmits the command to the corresponding NE. The network management apparatus then receives data in response to the command. By doing so, the state of the NE is changed, and the device status in the network is controlled. Also, to prevent a critical failure due to a wrong operation in the network, complicated restriction conditions are normally set in each NE.
Here, the restriction conditions refer to the rules about the relationships between the state of a NE and acceptable status change requests. For example, the restriction conditions specify that, when the NE is in a state of A, a command of a status change request A is acceptable, but a command of a status change request B is not acceptable.
Therefore, an operator needs to make a status change request so as to satisfy the restriction conditions. Upon receipt of a command of a status change request, a NE accepts the command if the command satisfies the restriction conditions, or returns an error response to the command to the network management apparatus if the command does not satisfy the restriction conditions, depending on the device status at that point.
To efficiently manage the history of operations such as command transmissions, each operator needs to skip unnecessary operations. When an operator is to send a status change request to a NE, the operator needs to confirm in advance whether the status change request satisfies the restriction conditions in the current NE state. By doing so, a proper status change request can be transmitted, and an error response from an NE can be avoided.
By the conventional management control, however, an operator needs to search for the restriction conditions for each status change request in advance, using the instruction manual or the help function for each NE, regardless of whether the NE is a newly introduced one or an old one. Furthermore, the operator needs to check whether the current device status satisfies the restriction conditions. Carrying out these processes is very troublesome, often resulting in a poor workability in maintenance management.
Also, if a command of a status change request is not accepted by a NE and an error response is sent from the NE, the operator has to find out the way to have the command accepted by the NE, studying the error contents, the current device state of the NE, and the restriction conditions or the like. Furthermore, if there are several solutions for the problem, the operator needs to try each solution. Accordingly, there are so many processes each operator has to carry out in the conventional network management operation, resulting in a poor operation efficiency.
Meanwhile, Japanese Laid-Open Patent Application No. 2000-339289 discloses a network management method. According to this method, the cause of trouble that can be estimated from the error contents and the solutions for the trouble are generated and stored in advance. When an error occurs, the possible causes of trouble and the solutions are displayed through the help function. The operator then determines the cause of trouble, and then inputs a new command.
In this conventional method, however, the current operation state of the NE is not taken into consideration, and the cause of trouble in the current state cannot be clearly pointed out. Therefore, the operator has to search for the cause of trouble and solutions, studying the possible causes of trouble and solutions. As a result, the operation efficiency is lowered. Furthermore, to produce solutions for problems in advance, it is necessary to store all the procedures of solving each problem. In such a case, some procedures unnecessary in the current operation state are also stored, resulting in a poorer management efficiency.